This invention relates to sausage stuffing horns commonly used in the packing of emulsions into sausage casings. More particularly, this invention relates to stuffing horns which invert and exchange the core or center portion of the stuffing material in order to improve the quality of the encased product and to improve the efficiency and economy of the sausage stuffing operation.
Stuffing horns are used on a stuffer apparatus which injects an emulsion of meat, fish, vegetable, protein or like material into casings. The resultant filled casings may then be further processed on linking equipment into sausages, e.g., fresh pork sausages, frankfurters, smoked sausage, etc. The casings, for example, Collagen casings of 25-100 foot (7.62-30.5 meter) lengths which have been shirred so that each casing strand has been compressed to a length of about 6-12 inches (15.2-30.5 cm.), are generally placed over the discharge end of the stuffing horn and receive the stuffing emulsion as it is fed from the apparatus through the stuffing horn. A number of problems exist, however, when the known stuffing horns are used.
The appearance, color and cooking performance especially of encased sausage meats are affected by the stuffing horn used in the packing operation. When travelling from the intake opening of the stuffing horn through the body and towards the discharge opening, the fatty portion of the meat emulsion tends to migrate toward the walls of the stuffing horn. When stuffed into the casing the fatty portion of meat settles at the inside surface of the sausage casing. The fatty portion of meat at the surface of the casing detracts from the appearance of the encased product since the color of the fatty emulsion has a smeared appearance rather than the bright, colorful appearance of the rich portion of the emulsion.
Besides an unattractive appearance, excess fat on the surface of the encased product detracts from the juiciness of the product since the juices inherent in the fat located at the outside surface of the casing are driven out during cooking.
It is believed that the smeared, fatty portion of meat is brought to the surface of the casing when the stuffing horn is too long or when the emulsion is driven too rapidly through the known types of stuffing horns. In order to eliminate the smearing and fat migrating problem, the stuffing horn has had to be relatively short, generally less than 9 inches, (22.9 cm.), or the speed of emulsion flow limited so as to prevent the fat from migrating outwardly.
When using the short stuffing horns the size of the shirred casing slug must be commensurate in length. The packed sausage casing is therefore shorter, with more changes and replacing of casings slugs occurring during the production operation. These changes, of course, undesirably slow down the packing process so that productivity rates decline and suffer.
Longer stuffing horns allow longer shirred casing slugs to be used and reduce the number of changes of slugs during packing. However, the longer horns, greater than 9 inches, (22.9 cm.), do not produce the same quality sausage as the shorter horns do to increased smearing of the emulsion at the surface of the encased emulsion.
Steps such as increasing the speed of stuffing the meat emulsion have been attempted, especially when using shorter horns, but to no effective avail. It has been determined that increased stuffing speeds enhance the migration of fatty portions toward the outside of the casings, resulting in an excessively smeared sausage. Consequently, a limiting compromise among length of stuffing horns, length of shirred casing slugs and speed of stuffing operation is practiced in the industry in order to maintain acceptable quality of the stuffed sausages.
There has been at least one attempt to overcome the problem of fat migrating to the surface of meat casings during the packing procedure. For example, U.S. Pat. No. 3,774,266 teaches the inclusion of a mixing gland at the outlet of a conventional stuffing horn. The mixing gland thoroughly mixes the meat emulsion just before being emptied into the casing, so the meat emulsion is sufficiently homogeneous throughout. Although the gland provides a uniform mixture of meat emulsion, its structure and purpose is to mix the meat emulsion uniformly, not to turn it over so that the fatty portion of meat is driven towards the center of the encased meat.